Our Axis2 service is currently implemented as you suggest and the xml is
streaming back to the client ok. The problem we're having is that the
memory footprint on the server is larger than we'd like.
We are creating a large xml result for a query in our Axis2 service
implementation. So we end up with a large xml result in a
ByteArrayOutputStream that we need to send back to the client. Using the
standard implementation suggested below doubles the memory footprint on the
server to create the OMElement that is returned by the service
implementation method. We'd like to be able to send the xml we have in
memory over the wire without creating the OMElment objects. Even better,
we'd like to start streaming back the xml result as it is being created. Is
there any way to implement an Axis2 service that either has OMElement
caching off when it streams back to the client or streams a result back to
the client as it is being created?
The code snippet below illustrates our failed attempts to make this work so
far:
//******* Standard Implementation
final ByteArrayOutputStream os = new
ByteArrayOutputStream();
//This method simply fills the os with xml
getDataObjectxml(snlModel, requiredAttrs, os);
ByteArrayInputStream bais = new
ByteArrayInputStream(os.toByteArray());
StAXOMBuilder builder = new StAXOMBuilder(bais);
//Turning off caching causes axis to hang on the retun
//It can't handle a non-caching OMElement
// builder.setCache(false);
dataOut = builder.getDocumentElement();
//***** Multi-threaded implementation
// //set up the streaming connections
// final PipedOutputStream pos = new PipedOutputStream();
// PipedInputStream pis = new PipedInputStream(pos);
//This implementation hangs here, attempting to create the
xml stream reader
// XMLStreamReader parser =
XMLInputFactory.newInstance().createXMLStreamReader(pis);
// StAXOMBuilder builder = new StAXOMBuilder(parser);
// dataOut = builder.getDocumentElement();
//
// //write to the stream on a separate thread
// Runnable xmlRunnable = new Runnable() {
// public void run() {
// try {
// getDataObjectxml(snlModel, requiredAttrs,
pos);
// } catch (Exception e) {
// e.printStackTrace(); //To change body of
catch statement use File | Settings | File Templates.
// }
// }
// };
// Thread serializerThread = new Thread(xmlRunnable);
// serializerThread.start();
Lakshmi Chaparala
-----Original Message-----
From: Srinath Perera [mailto:[EMAIL PROTECTED]
Sent: Thursday, March 02, 2006 11:07 AM
To: [email protected]
Subject: Re: Axis2 and Streaming
If you create a OM element as follows by providing a Stream, the
stream is not really read
unless you accsess the OMElement. So If you create a OM element like
follwoing and use it in Axis2 .. it should do streaming
File file= new File("line-item.xml");
FileInputStream fis= new FileInputStream(file);
XMLInputFactory xif= XMLInputFactory.newInstance();
XMLStreamReader reader= xif.createXMLStreamReader(fis);
StAXOMBuilder builder= new StAXOMBuilder(reader);
OMElement lineItem= builder.getDocumentElement();
See http://www-128.ibm.com/developerworks/library/x-axiom/ for more info
--Srinath
